Any advice from breaking into US market?

I currently do website development for small businesses, mainly estate agents, over the past year and a bit I've built up a decent MRR. I'm looking to break into the US market to expand my business as I'm starting to find UK businesses just don't have as much money to spend on websites and there are obviously far less. Does anyone have any advice for things to consider? Such as payments, marketing in the US, keeping it legal etc. And whether it was worth it to you? TYIA